At the initial stage of development of the touch display technology, a touch display panel is formed by a combination of a touch panel and a display panel to achieve a touch display function. In this case, the touch panel and the display panel are fabricated independently, resulting in high cost, substantial thickness and low production efficiency.
With the development of self-contained touch display technology, a common electrode of an array substrate of the display panel may also be used as a touch sensing electrode for a self-contained touch detection, and both the touch function and the display function may be achieved by performing touch control and display control in a time-sharing driving manner. In this case, the touch sensing electrode is integrated in the display panel directly, thereby reducing the fabrication cost and the thickness of the panel and improving the production efficiency.
FIG. 1 is a schematic structural diagram of a general touch display substrate according to conventional technologies. The touch display substrate includes a common electrode layer and a wire layer arranged opposite to each other on a substrate. The common electrode layer includes multiple common electrodes 11 arranged in an array. The wire layer includes multiple wires 12 connected to the common electrodes 11 in a one-to-one way. An insulation layer is arranged between an end of the wire 12 and the common electrode 11. The end of the wire 12 is connected to the common electrode 11 through a via hole 13, and the other end of the wire 12 is connected to a control circuit 14.
As can be seen in FIG. 1, in a column of common electrodes 11 of the conventional touch display substrate, a wire 12 connected to a common electrode 11 at a distal end of the column (an end of the column far away from the control circuit 14) is connected to a touch detection amplifier 14 in a way of striding over other common electrodes 11 in the same column. In this case, a touch detection signal transmitted in the wire 12 may be coupled to other common electrodes in the same column via parasitic capacitances, thereby resulting in serious vertical crosstalk and affecting the accuracy of the touch detection.